1. Field of the Invention
The present invention relates to an automated process and apparatus for assembling and aligning a laser.
2. Art Background
Lasers are complex devices that consist of many components. Certain lasers contain, among other components, a lens for focusing the radiation to produce a high intensity beam of light and a transmission assembly. The transmission assembly conducts the high intensity beam of light to a location remote from the lens. The high intensity beam of light is used for a number of different purposes well known to people familiar with these types of devices.
The lens and the transmission assembly are operatively connected together. In certain instances, the lens is preassembled in a lens housing and the transmission assembly is an optical fiber that is preattached to a ferrule and sleeve subassembly. To complete the laser assembly, the ferrule/sleeve subassembly is operatively coupled to the preassembled lens housing.
The lens housing and the ferrule/sleeve assembly cannot simply be connected to ensure acceptable laser operation, however. The lens housing and the ferrule/sleeve assembly must be coupled together in a manner that ensures that the lens and optical fiber are in proper alignment. If the lens and the optical fiber are not properly aligned, the power of the light transmitted by the fiber is unnecessarily low.
Currently, a complex manual manipulation of the lens housing and the ferrule/sleeve assembly is performed to align and assemble these components. First, the four leads extending from the lens housing are inserted into a socket. The socket also has leads extending from it. Each of the leads is inserted into a separate opening in the socket. When the lens housing leads are placed in the socket openings, an electrical connection between the lens housing leads and the socket leads is formed.
The lens housing leads are made of thin gauge wire and are easily bent. However, although these wires are easily bent, it is time consuming and difficult to properly place such wires in a corresponding opening in the socket. Furthermore, because these wires are easily bent, it is possible to bend them into contact with each other.
The lens housing is then connected to the ferrule/sleeve assembly, but they are aligned before they are affixed to each other. To align the lens and the optical fiber, the socket leads are connected to a source of electric power. Electric current is then supplied to the lens housing--ferrule/sleeve assembly. The alignment of the lens is determined by measuring the current supplied to the lens housing and the energy of the beam of light transmitted through the optical fiber.
The way in which these two parameters indicate the alignment of the lens and the optical fiber is based on the relationship of the components in these types of devices. The beam of light that is focused by the lens and transmitted by the fiber is generated by a device that is also present in the housing. Such devices are typically referred to as chips. The electric current supplied to the chip provides the current necessary for the chip to generate the beam of light.
The chip operates at a certain efficiency. For every chip, a certain amount of electric current (X) will generate a beam of light with a certain energy (Y). Whether the chip is operating at its desired efficiency is determined by measuring the current provided to the housing and the energy of the beam of light from the fiber. If the amount of electric current provided is X, but the energy or power of the beam of light is less than Y, then the chip is not operating at its desired efficiency.
One factor that can effect chip performance is the alignment of the lens and the fiber. If the lens does not properly aim the high intensity beam of light at the fiber, the chip works harder to transmit a less powerful beam of light. The harder the chip works, the more power it consumes.
If the power of the light beam is observed to be unacceptably low based on the electric current provided to the chip, the lens housing and the ferrule/sleeve assembly are moved in relation to each other until the power of the light beam reaches an acceptable level. When the power of the light beam is acceptable based on the electric current provided to the device, the high intensity beam of light is properly aimed at the transmission assembly. The lens housing and the ferrule/sleeve assembly are then affixed to each other by laser welding or some other acceptable means. The process for aligning the housing and the ferrule/sleeve assembly uses conventional methods to manipulate the lens housing relative to the ferrule/sleeve assembly until the power of the light beam transmitted through the optical fiber is acceptably high.
The manual manipulation of the leads into the socket for purposes of testing the alignment of these devices is inefficient and time consuming. The manual placement of the lens housing in an apparatus that will align the housing with the ferrule/sleeve assembly is also time consuming. Therefore, an automated process that assembles and aligns the laser components is desired.